Class 12 Chemistry – Electrochemistry MCQs
Basic Concepts of Electrochemistry
- Electrochemistry deals with the relationship between:
A. Chemical reactions and heat energy
B. Chemical reactions and electrical energy
C. Chemical reactions and mechanical energy
D. Chemical reactions and light energy - A device that converts chemical energy into electrical energy is known as:
A. Electrolytic cell
B. Galvanic cell
C. Fuel burner
D. Calorimeter - In an electrochemical cell, oxidation takes place at the:
A. Cathode
B. Anode
C. Salt bridge
D. Electrolyte - Reduction in an electrochemical cell occurs at the:
A. Cathode
B. Anode
C. Salt bridge
D. Metal electrode - The flow of electrons in an external circuit is from:
A. Cathode to anode
B. Anode to cathode
C. Electrolyte to electrode
D. Salt bridge to electrode - The electrode at which reduction occurs is called:
A. Anode
B. Cathode
C. Neutral electrode
D. Reference electrode - The electrode at which oxidation occurs is called:
A. Cathode
B. Anode
C. Neutral electrode
D. Salt electrode - In a galvanic cell, chemical energy is converted into:
A. Mechanical energy
B. Electrical energy
C. Heat energy
D. Nuclear energy - In an electrolytic cell, electrical energy is converted into:
A. Chemical energy
B. Mechanical energy
C. Heat energy
D. Nuclear energy - The component used to maintain electrical neutrality in an electrochemical cell is:
A. Wire
B. Salt bridge
C. Electrode
D. Voltmeter
Galvanic Cells
- A galvanic cell is also known as:
A. Voltaic cell
B. Photovoltaic cell
C. Solar cell
D. Dry cell - The Daniell cell consists of electrodes made of:
A. Iron and copper
B. Zinc and copper
C. Silver and gold
D. Aluminum and copper - In a Daniell cell, zinc electrode acts as:
A. Cathode
B. Anode
C. Salt bridge
D. Electrolyte - In a Daniell cell, copper electrode acts as:
A. Anode
B. Cathode
C. Salt bridge
D. Electrolyte - The movement of ions through the salt bridge helps to:
A. Increase voltage
B. Maintain charge balance
C. Produce electrons
D. Reduce temperature - If the salt bridge is removed from a galvanic cell, the cell will:
A. Work normally
B. Stop working after some time
C. Increase current
D. Increase voltage - In a galvanic cell, electrons travel through:
A. Electrolyte
B. Salt bridge
C. External circuit
D. Cathode solution - The cell potential of a galvanic cell depends on:
A. Nature of electrodes
B. Concentration of electrolytes
C. Temperature
D. All of these
Electrode Potential
- Electrode potential is a measure of:
A. Ability of an electrode to gain or lose electrons
B. Resistance of a metal
C. Density of electrolyte
D. Conductivity of electrode - Standard electrode potential is measured under:
A. 1 atm pressure
B. 298 K temperature
C. 1 M concentration
D. All of these - The reference electrode used to measure electrode potential is:
A. Copper electrode
B. Zinc electrode
C. Standard hydrogen electrode
D. Platinum electrode - The standard potential of the standard hydrogen electrode is:
A. 1 V
B. 0 V
C. –1 V
D. 0.5 V - The electrode potential measured relative to the standard hydrogen electrode is called:
A. Absolute potential
B. Standard reduction potential
C. Oxidation potential
D. Neutral potential - The electrode with higher reduction potential will:
A. Lose electrons easily
B. Gain electrons easily
C. Remain unchanged
D. Form precipitate
Nernst Equation
- The Nernst equation is used to calculate:
A. Resistance of solution
B. Cell potential under non-standard conditions
C. Conductivity of solution
D. Temperature of reaction - The Nernst equation relates cell potential with:
A. Concentration of ions
B. Temperature
C. Reaction quotient
D. All of these - The Nernst equation becomes simpler at temperature:
A. 273 K
B. 298 K
C. 300 K
D. 350 K - In the Nernst equation, the term “n” represents:
A. Number of ions
B. Number of electrons transferred
C. Number of molecules
D. Number of electrodes
Conductance of Electrolytic Solutions
- Conductance is the reciprocal of:
A. Voltage
B. Resistance
C. Current
D. Charge - The SI unit of conductance is:
A. Ohm
B. Siemens
C. Volt
D. Ampere - Conductivity of a solution depends on:
A. Nature of electrolyte
B. Concentration of ions
C. Temperature
D. All of these - Specific conductance is defined as the conductance of:
A. One mole of electrolyte
B. One gram of electrolyte
C. Solution of unit volume
D. One liter of solution - Molar conductivity is represented by the symbol:
A. κ
B. Λm
C. μ
D. σ - Molar conductivity increases with:
A. Increase in concentration
B. Decrease in dilution
C. Increase in dilution
D. Increase in pressure
Kohlrausch’s Law
- Kohlrausch’s law states that at infinite dilution:
A. Ions move together
B. Ions migrate independently
C. Conductivity becomes zero
D. Electrolytes stop dissociating - Kohlrausch’s law is useful for determining:
A. Conductivity of strong electrolytes
B. Molar conductivity of weak electrolytes at infinite dilution
C. Resistance of metals
D. Density of electrolytes
Electrolysis
- Electrolysis is the process of:
A. Decomposition of substances using electricity
B. Formation of electricity from heat
C. Production of light from electricity
D. Production of heat from electricity - During electrolysis, reduction occurs at:
A. Anode
B. Cathode
C. Salt bridge
D. Electrolyte - During electrolysis, oxidation occurs at:
A. Cathode
B. Anode
C. Salt bridge
D. Wire - The amount of substance deposited during electrolysis depends on:
A. Quantity of electricity passed
B. Nature of electrolyte
C. Temperature
D. Pressure
Faraday’s Laws of Electrolysis
- Faraday’s first law states that the mass of substance deposited is proportional to:
A. Temperature
B. Charge passed
C. Voltage
D. Resistance - Faraday’s second law relates mass deposited to:
A. Equivalent weight of substance
B. Density of electrolyte
C. Volume of electrolyte
D. Temperature - One Faraday corresponds to approximately:
A. 96500 coulombs
B. 965 coulombs
C. 9650 coulombs
D. 96 coulombs
Corrosion
- Corrosion is defined as:
A. Formation of alloys
B. Gradual destruction of metals by chemical reaction
C. Formation of oxides by heating
D. Dissolution of metals in water - Rusting of iron requires the presence of:
A. Oxygen only
B. Water only
C. Oxygen and water
D. Carbon dioxide - Rust mainly consists of:
A. Iron oxide
B. Hydrated iron(III) oxide
C. Iron carbonate
D. Iron chloride - The method used to prevent corrosion by coating iron with zinc is called:
A. Electroplating
B. Galvanization
C. Alloying
D. Anodizing
- The electrochemical cell in which electrical energy is supplied to drive a non-spontaneous reaction is called:
A. Galvanic cell
B. Electrolytic cell
C. Dry cell
D. Concentration cell - The direction of electron flow in an electrolytic cell is from:
A. Cathode to anode
B. Power source to cathode
C. Electrolyte to electrode
D. Salt bridge to electrode - In an electrochemical cell, the electrode potential depends on:
A. Nature of electrode
B. Concentration of ions in solution
C. Temperature
D. All of these - The difference between the electrode potentials of two electrodes in a cell is called:
A. Cell voltage
B. Cell potential
C. Electromotive force
D. All of these - The standard electrode potentials are usually tabulated as:
A. Oxidation potentials
B. Reduction potentials
C. Neutral potentials
D. Absolute potentials - The electrode with lower reduction potential acts as:
A. Cathode
B. Anode
C. Neutral electrode
D. Reference electrode - In the electrochemical series, metals placed higher in the series are:
A. Stronger reducing agents
B. Stronger oxidizing agents
C. Less reactive metals
D. Noble metals - A metal that has a very negative standard reduction potential tends to:
A. Gain electrons easily
B. Lose electrons easily
C. Remain stable
D. Form covalent bonds - The ability of a species to accept electrons is known as:
A. Oxidation power
B. Reducing power
C. Oxidizing power
D. Conducting power - The ability of a species to donate electrons is known as:
A. Oxidizing power
B. Reducing power
C. Neutral power
D. Conducting power - The spontaneous direction of a redox reaction can be predicted using:
A. Electrochemical series
B. Periodic table
C. Gas laws
D. Boyle’s law - If the standard cell potential is positive, the reaction is:
A. Non-spontaneous
B. Spontaneous
C. Impossible
D. Neutral - If the standard cell potential is negative, the reaction is:
A. Spontaneous
B. Non-spontaneous
C. Explosive
D. Irreversible - The relationship between Gibbs free energy and cell potential is given by:
A. ΔG = nFE
B. ΔG = –nFE
C. ΔG = FE
D. ΔG = nF/E - When ΔG is negative, the reaction is:
A. Spontaneous
B. Non-spontaneous
C. Equilibrium
D. Impossible - The Faraday constant represents the charge carried by:
A. One mole of atoms
B. One mole of electrons
C. One mole of ions
D. One mole of molecules - Conductivity of a solution mainly depends on:
A. Number of ions present
B. Mobility of ions
C. Nature of solvent
D. All of these - The conductance of electrolytic solutions increases with:
A. Increase in temperature
B. Decrease in temperature
C. Increase in pressure
D. Decrease in ions - Strong electrolytes are substances that:
A. Partially ionize in solution
B. Completely ionize in solution
C. Do not ionize in solution
D. Form precipitates - Weak electrolytes are substances that:
A. Completely ionize in solution
B. Partially ionize in solution
C. Do not dissolve in water
D. Form gases - The limiting molar conductivity is the molar conductivity at:
A. Zero concentration
B. Infinite dilution
C. High temperature
D. High pressure - At infinite dilution, interionic attractions between ions:
A. Increase
B. Become negligible
C. Become very strong
D. Stop ion movement - The main cause of corrosion of metals is:
A. Electrochemical reactions
B. Mechanical stress
C. High temperature
D. Low pressure - The corrosion of iron results in formation of:
A. Iron sulfate
B. Iron carbonate
C. Hydrated iron oxide
D. Iron chloride - The presence of salts in water generally:
A. Decreases corrosion
B. Increases corrosion
C. Stops corrosion
D. Has no effect - Cathodic protection is a method used to:
A. Increase corrosion
B. Prevent corrosion
C. Increase conductivity
D. Produce electricity - In cathodic protection, the metal to be protected is made the:
A. Cathode
B. Anode
C. Electrolyte
D. Salt bridge - A sacrificial anode is usually made of:
A. Less reactive metal
B. More reactive metal
C. Noble metal
D. Non-metal - Electroplating is the process of:
A. Coating one metal with another using electricity
B. Removing metal layers
C. Heating metals in furnace
D. Mixing two metals - In electroplating, the object to be plated is made the:
A. Anode
B. Cathode
C. Electrolyte
D. Salt bridge - The metal used for coating during electroplating is connected to:
A. Cathode
B. Anode
C. Electrolyte
D. Power supply - The electrolyte used in electroplating usually contains:
A. Salt of coating metal
B. Salt of base metal
C. Water only
D. Acid only - A concentration cell is an electrochemical cell in which:
A. Electrodes are different metals
B. Electrolytes have different concentrations
C. No electrolyte is used
D. No current flows
Class 12 Chemistry – Electrochemistry MCQs (Next Set)
- The potential difference between two electrodes when no current flows through the circuit is called:
A. Electromotive force
B. Conductivity
C. Resistance
D. Charge density - The electromotive force of a cell is usually measured using:
A. Ammeter
B. Voltmeter
C. Galvanometer
D. Ohmmeter - The potential of an individual electrode cannot be measured directly because:
A. Electrodes are unstable
B. Current does not flow
C. A single electrode potential cannot exist independently
D. Electrolytes are absent - The standard hydrogen electrode uses hydrogen gas at pressure:
A. 2 atm
B. 1 atm
C. 0.5 atm
D. 5 atm - In the standard hydrogen electrode, the electrode material used is:
A. Copper
B. Zinc
C. Platinum
D. Iron - The hydrogen ions in the standard hydrogen electrode solution have concentration:
A. 0.1 M
B. 0.5 M
C. 1 M
D. 2 M - The standard hydrogen electrode mainly acts as a:
A. Oxidizing agent
B. Reducing agent
C. Reference electrode
D. Catalyst - If a metal displaces hydrogen from acid, its standard reduction potential is:
A. Greater than zero
B. Less than zero
C. Equal to zero
D. Infinite - A metal placed lower in the electrochemical series is:
A. More reactive
B. Less reactive
C. Highly unstable
D. Non-metallic - Noble metals generally have:
A. Negative reduction potential
B. Positive reduction potential
C. Zero reduction potential
D. Infinite reduction potential - The conductivity of pure water is very low because:
A. It contains no ions
B. It contains very few ions
C. It contains too many ions
D. It forms precipitates - The unit of molar conductivity is:
A. S cm² mol⁻¹
B. S cm⁻¹
C. Ohm cm
D. Volt cm - The conductance of a solution increases when:
A. Length of conductor increases
B. Area of cross-section increases
C. Resistance increases
D. Temperature decreases - Specific conductance depends on:
A. Nature of electrolyte
B. Concentration of ions
C. Temperature
D. All of these - In dilute solutions, molar conductivity of weak electrolytes increases sharply because:
A. Degree of ionization increases
B. Ion mobility decreases
C. Temperature decreases
D. Density increases - Weak electrolytes show higher increase in molar conductivity with dilution due to:
A. Increased ionization
B. Decreased ionization
C. Ion precipitation
D. Molecular association - The limiting molar conductivity of an electrolyte is denoted by:
A. Λm°
B. κ
C. μ
D. σ - Kohlrausch’s law is mainly applicable at:
A. High concentration
B. Infinite dilution
C. High temperature
D. High pressure - According to Kohlrausch’s law, each ion contributes:
A. Equally to conductivity
B. Independently to conductivity
C. Negatively to conductivity
D. Randomly to conductivity - The total limiting molar conductivity of an electrolyte equals:
A. Sum of ionic conductivities
B. Product of ionic conductivities
C. Difference of ionic conductivities
D. Square of ionic conductivities - Electrolysis of water produces hydrogen gas at:
A. Anode
B. Cathode
C. Salt bridge
D. Electrolyte - Oxygen gas during electrolysis of water is produced at:
A. Cathode
B. Anode
C. Wire
D. Salt bridge - During electrolysis, positively charged ions move towards:
A. Anode
B. Cathode
C. Salt bridge
D. Power supply - During electrolysis, negatively charged ions move towards:
A. Cathode
B. Anode
C. Electrolyte
D. Salt bridge - The movement of ions under the influence of electric field is called:
A. Diffusion
B. Migration
C. Conduction
D. Filtration - The decomposition potential is the:
A. Minimum voltage required for electrolysis
B. Maximum voltage applied
C. Voltage produced in cell
D. Voltage lost in wire - The electrolysis of molten salts generally produces:
A. Pure metals
B. Alloys
C. Non-metals only
D. Organic compounds - The process of coating iron with chromium to prevent corrosion is called:
A. Galvanization
B. Chromium plating
C. Alloying
D. Cathodic protection - In electroplating, the thickness of coating depends on:
A. Time of electrolysis
B. Current passed
C. Nature of electrolyte
D. All of these - In corrosion, the metal surface acts like a:
A. Battery
B. Fuel cell
C. Electrochemical cell
D. Solar cell
Class 12 Chemistry – Electrochemistry MCQs (Next Set)
- The relation between conductance (G) and resistance (R) is:
A. G = R
B. G = 1/R
C. G = R²
D. G = R/2 - Resistance of a conductor increases when:
A. Length increases
B. Area of cross section increases
C. Temperature increases
D. Number of ions increases - The resistance of a solution depends on:
A. Length of solution column
B. Cross-sectional area
C. Nature of electrolyte
D. All of these - Conductivity is the reciprocal of:
A. Resistance
B. Resistivity
C. Voltage
D. Current - The cell constant of a conductivity cell is given by:
A. Length × Area
B. Length / Area
C. Area / Length
D. Length + Area - The unit of cell constant is:
A. cm
B. cm⁻¹
C. mol⁻¹
D. S cm⁻¹ - Conductometric titrations are based on measurement of:
A. Temperature
B. Pressure
C. Conductivity
D. Density - Conductometric titration is especially useful for titration of:
A. Strong acid and strong base
B. Weak acid and weak base
C. Neutral solutions
D. Insoluble salts - In conductometric titration, the end point is determined by:
A. Colour change
B. Conductivity change
C. Temperature change
D. Pressure change - Strong electrolytes show small increase in molar conductivity with dilution because:
A. They are already highly ionized
B. They do not ionize
C. Ions disappear
D. Conductivity becomes zero - Weak electrolytes have low conductivity because:
A. They produce fewer ions
B. They produce many ions
C. They do not dissolve
D. They form solids - Ionic mobility refers to:
A. Speed of ions in electric field
B. Mass of ions
C. Size of ions
D. Charge on ions - The migration of ions towards electrodes during electrolysis is due to:
A. Electric field
B. Temperature
C. Pressure
D. Gravity - The amount of substance liberated during electrolysis is proportional to:
A. Voltage applied
B. Current and time
C. Resistance
D. Temperature - Electrolysis of aqueous sodium chloride produces hydrogen gas at:
A. Anode
B. Cathode
C. Salt bridge
D. Wire - During electrolysis of aqueous NaCl, chlorine gas is liberated at:
A. Cathode
B. Anode
C. Electrolyte
D. Salt bridge - Electrolysis of molten sodium chloride produces:
A. Sodium metal and chlorine gas
B. Sodium hydroxide and hydrogen
C. Sodium carbonate and oxygen
D. Sodium sulfate and hydrogen - The oxidation number of a metal increases during:
A. Oxidation
B. Reduction
C. Neutralization
D. Precipitation - In corrosion of iron, the anodic reaction involves:
A. Oxidation of iron
B. Reduction of iron
C. Formation of hydrogen gas
D. Formation of carbon dioxide - In rusting of iron, oxygen acts as:
A. Reducing agent
B. Oxidizing agent
C. Catalyst
D. Neutral substance - The cathodic reaction during rusting of iron involves:
A. Reduction of oxygen
B. Oxidation of oxygen
C. Oxidation of iron
D. Formation of salt bridge - Painting metal surfaces prevents corrosion by:
A. Increasing conductivity
B. Preventing contact with air and moisture
C. Increasing oxidation
D. Decreasing temperature - Alloying helps in preventing corrosion by:
A. Changing metal composition
B. Increasing moisture absorption
C. Increasing oxidation rate
D. Producing gases - Stainless steel resists corrosion because it contains:
A. Chromium
B. Sodium
C. Calcium
D. Zinc - The process of coating iron with tin is called:
A. Tinning
B. Galvanization
C. Alloying
D. Electrolysis - The electrode where oxidation occurs always has:
A. Loss of electrons
B. Gain of electrons
C. No electron transfer
D. Equal electrons - The electrode where reduction occurs always has:
A. Loss of electrons
B. Gain of electrons
C. No ion formation
D. No reaction - The standard cell potential is represented by:
A. E°cell
B. ΔG°
C. κ
D. Λm - The unit of electrode potential is:
A. Volt
B. Ampere
C. Ohm
D. Coulomb - When the cell reaches equilibrium, the cell potential becomes:
A. Maximum
B. Minimum
C. Zero
D. Infinite
- The equilibrium constant of a cell reaction is related to:
A. Cell potential
B. Temperature
C. Number of electrons transferred
D. All of these - When the equilibrium constant of a reaction is very large, the cell potential is:
A. Negative
B. Positive
C. Zero
D. Infinite - A spontaneous electrochemical reaction has:
A. Negative cell potential
B. Positive cell potential
C. Zero cell potential
D. Infinite resistance - The charge required to deposit one gram equivalent of a substance during electrolysis is:
A. One coulomb
B. One faraday
C. One volt
D. One ampere - The Faraday constant is approximately equal to:
A. 9.65 × 10⁴ C mol⁻¹
B. 9.65 × 10³ C mol⁻¹
C. 9.65 × 10² C mol⁻¹
D. 9.65 × 10⁵ C mol⁻¹ - The electrochemical equivalent of a substance is defined as the:
A. Mass deposited by one coulomb of electricity
B. Mass deposited by one volt
C. Mass deposited by one ampere
D. Mass deposited by one mole - If the current passed through an electrolytic cell increases, the amount of substance deposited will:
A. Increase
B. Decrease
C. Remain constant
D. Become zero - The quantity of electricity passed through an electrolytic solution is given by:
A. Q = V/R
B. Q = I × t
C. Q = R × t
D. Q = V × R - During electrolysis, the electrode connected to the positive terminal of the power supply is the:
A. Cathode
B. Anode
C. Salt bridge
D. Electrolyte - During electrolysis, the electrode connected to the negative terminal of the power supply is the:
A. Cathode
B. Anode
C. Salt bridge
D. Power source - The electrochemical series helps to predict:
A. Feasibility of redox reactions
B. Relative reactivity of metals
C. Ability of metals to displace hydrogen
D. All of these - Metals with very positive reduction potentials are generally:
A. Highly reactive
B. Less reactive
C. Strong reducing agents
D. Easily oxidized - Metals with very negative reduction potentials are generally:
A. Strong reducing agents
B. Strong oxidizing agents
C. Noble metals
D. Non-reactive - A concentration cell generates electricity because of:
A. Difference in electrode materials
B. Difference in electrolyte concentration
C. Difference in temperature
D. Difference in pressure - In a concentration cell, the electrodes are usually:
A. Different metals
B. Same metal
C. Non-metals
D. Inert gases - The current produced in a concentration cell continues until:
A. Electrodes dissolve
B. Concentrations become equal
C. Temperature becomes zero
D. Salt bridge stops working - In corrosion, the metal that corrodes acts as:
A. Cathode
B. Anode
C. Electrolyte
D. Insulator - During corrosion of iron, electrons released at the anodic region move to:
A. Cathodic region
B. Salt bridge
C. Air
D. Water - The presence of acidic environment generally:
A. Decreases corrosion
B. Increases corrosion
C. Stops corrosion
D. Has no effect - The presence of dissolved oxygen in water:
A. Prevents rusting
B. Accelerates rusting
C. Stops electrochemical reactions
D. Reduces oxidation - Protective oxide layers on metals can prevent corrosion in:
A. Aluminum
B. Chromium
C. Zinc
D. All of these - Anodizing is a process used mainly for protection of:
A. Iron
B. Aluminum
C. Copper
D. Silver - In anodizing, the metal surface is converted into:
A. Thick oxide layer
B. Metal chloride layer
C. Metal carbonate layer
D. Pure metal - The process of purifying metals using electrolysis is called:
A. Electroplating
B. Electrorefining
C. Galvanization
D. Alloying - In electrorefining, the impure metal is used as:
A. Cathode
B. Anode
C. Electrolyte
D. Salt bridge - In electrorefining, the pure metal is deposited at the:
A. Anode
B. Cathode
C. Electrolyte
D. Power supply - The insoluble impurities that settle at the bottom during electrorefining are called:
A. Anode mud
B. Cathode mud
C. Salt deposits
D. Metal oxide - Fuel cells generate electricity by:
A. Combustion reactions
B. Electrochemical reactions
C. Nuclear reactions
D. Photochemical reactions - A common fuel used in fuel cells is:
A. Hydrogen
B. Nitrogen
C. Helium
D. Neon - In a hydrogen–oxygen fuel cell, the main product formed is:
A. Water
B. Carbon dioxide
C. Hydrogen peroxide
D. Oxygen gas - Fuel cells are considered environmentally friendly because they:
A. Produce little pollution
B. Produce no electricity
C. Consume large energy
D. Produce heavy metals - The efficiency of fuel cells is generally:
A. Very low
B. Moderate
C. High
D. Zero - Batteries used in electronic devices are examples of:
A. Electrochemical cells
B. Nuclear cells
C. Solar cells
D. Thermal cells - A dry cell commonly used in flashlights is an example of:
A. Primary battery
B. Secondary battery
C. Fuel cell
D. Solar cell - Primary batteries are those which:
A. Cannot be recharged
B. Can be recharged
C. Produce unlimited electricity
D. Work only once per second - Secondary batteries are those which:
A. Cannot be reused
B. Can be recharged and reused
C. Produce no electricity
D. Work only at high temperature - The lead-acid battery used in automobiles is an example of:
A. Primary cell
B. Secondary cell
C. Fuel cell
D. Solar cell - During discharge of a lead-acid battery, lead reacts with:
A. Sulfuric acid
B. Hydrochloric acid
C. Nitric acid
D. Acetic acid - During charging of a rechargeable battery, electrical energy is converted into:
A. Heat energy
B. Chemical energy
C. Mechanical energy
D. Nuclear energy - Electrochemical cells operate based on:
A. Oxidation-reduction reactions
B. Neutralization reactions
C. Precipitation reactions
D. Polymerization reactions
NEET-Focused Electrochemistry MCQs
- A galvanic cell is made of Zn/Zn²⁺ and Cu/Cu²⁺. If [Zn²⁺] = 0.01 M and [Cu²⁺] = 1 M, the EMF of the cell at 298 K is approximately (E°Zn²⁺/Zn = –0.76 V, E°Cu²⁺/Cu = +0.34 V):
A. 1.10 V B. 1.15 V C. 1.05 V D. 1.00 V - In a concentration cell with Cu/Cu²⁺ electrodes, [Cu²⁺] = 0.01 M in one half-cell and 1 M in the other. The EMF of the cell at 298 K is:
A. 0.029 V B. 0.059 V C. 0.118 V D. 0.177 V - How many grams of Ag are deposited when a current of 2 A is passed through AgNO₃ solution for 30 minutes? (Ag = 107 g/mol, 1 F = 96500 C)
A. 0.33 g B. 0.53 g C. 1.07 g D. 0.64 g - The number of electrons involved in the reaction Zn → Zn²⁺ + 2e⁻ is:
A. 1 B. 2 C. 3 D. 4 - A cell is represented as: Zn(s) | Zn²⁺(0.1 M) || Cu²⁺(1 M) | Cu(s). The anode is:
A. Zn(s) B. Cu(s) C. Cu²⁺(aq) D. Zn²⁺(aq) - Faraday’s first law of electrolysis states:
A. Mass deposited ∝ Current × Time
B. Mass deposited ∝ Voltage
C. Mass deposited ∝ Resistance
D. Mass deposited ∝ Power - During electrolysis of water, the volume ratio of hydrogen to oxygen is:
A. 2:1 B. 1:2 C. 1:1 D. 3:1 - Which of the following metals is most resistant to corrosion?
A. Fe B. Zn C. Al D. Na - A solution contains 0.01 M NaCl. Its molar conductivity at infinite dilution is 126.4 S cm² mol⁻¹. The conductivity (κ) of the solution is approximately:
A. 0.0126 S cm⁻¹ B. 0.126 S cm⁻¹ C. 1.26 S cm⁻¹ D. 12.6 S cm⁻¹ - EMF of a cell depends on:
A. Electrode materials only
B. Concentration of ions only
C. Both electrode and ion concentration
D. Neither - In a redox reaction, a positive E°cell implies:
A. Non-spontaneous reaction
B. Spontaneous reaction
C. Equilibrium
D. No reaction - The charge required to deposit 1 mole of Cu (Cu²⁺ + 2e⁻ → Cu) is:
A. 96500 C B. 1.93 × 10⁵ C C. 4.83 × 10⁴ C D. 2 × 96500 C - In electroplating, the thickness of the deposited layer can be increased by:
A. Increasing current B. Increasing time C. Both A & B D. None - Which of the following pairs can form a concentration cell?
A. Zn/Zn²⁺ and Cu/Cu²⁺ B. Cu/Cu²⁺ and Cu/Cu²⁺ with different concentrations C. Mg/Mg²⁺ and Zn/Zn²⁺ D. Fe/Fe²⁺ and Zn/Zn²⁺ - For the reaction: 2Ag⁺ + Cu → 2Ag + Cu²⁺, the metal which gets oxidized is:
A. Ag B. Cu C. Both D. None - In a lead-acid battery, during discharge, the chemical energy is converted into:
A. Heat energy B. Electrical energy C. Mechanical energy D. Light energy - A galvanic cell has E°cell = 1.10 V. If 0.5 mole of electrons is transferred, ΔG° is approximately: (F = 96500 C/mol)
A. –53275 J B. –53275 kJ C. 53275 kJ D. 53275 J - The main purpose of a salt bridge in a galvanic cell is:
A. To increase voltage B. To maintain electrical neutrality C. To act as an electrode D. To react with ions - In a hydrogen-oxygen fuel cell, the overall reaction is:
A. 2H₂ + O₂ → 2H₂O B. H₂ + O₂ → H₂O₂ C. H₂ + O₂ → H₂O₂ D. H₂ + O → H₂O - Which factor does NOT affect corrosion rate?
A. Oxygen availability B. Humidity C. Temperature D. Atomic mass of metal
| Q.No | Answer | Q.No | Answer | Q.No | Answer |
|---|---|---|---|---|---|
| 1 | B | 61 | B | 121 | A |
| 2 | B | 62 | A | 122 | A |
| 3 | B | 63 | B | 123 | A |
| 4 | A | 64 | D | 124 | B |
| 5 | B | 65 | A | 125 | B |
| 6 | B | 66 | B | 126 | B |
| 7 | B | 67 | B | 127 | A |
| 8 | B | 68 | B | 128 | A |
| 9 | A | 69 | B | 129 | A |
| 10 | B | 70 | A | 130 | B |
| 11 | A | 71 | C | 131 | A |
| 12 | B | 72 | B | 132 | B |
| 13 | B | 73 | B | 133 | A |
| 14 | B | 74 | A | 134 | A |
| 15 | B | 75 | B | 135 | A |
| 16 | B | 76 | A | 136 | A |
| 17 | C | 77 | B | 137 | B |
| 18 | D | 78 | B | 138 | A |
| 19 | A | 79 | A | 139 | A |
| 20 | D | 80 | B | 140 | C |
| 21 | C | 81 | B | 141 | D |
| 22 | B | 82 | B | 142 | B |
| 23 | B | 83 | C | 143 | B |
| 24 | B | 84 | B | 144 | B |
| 25 | B | 85 | C | 145 | A |
| 26 | D | 86 | C | 146 | A |
| 27 | B | 87 | C | 147 | A |
| 28 | B | 88 | B | 148 | B |
| 29 | B | 89 | B | 149 | B |
| 30 | B | 90 | B | 150 | A |
| 31 | D | 91 | B | 151 | D |
| 32 | C | 92 | A | 152 | B |
| 33 | B | 93 | B | 153 | A |
| 34 | C | 94 | D | 154 | B |
| 35 | B | 95 | A | 155 | B |
| 36 | B | 96 | A | 156 | B |
| 37 | A | 97 | A | 157 | B |
| 38 | B | 98 | B | 158 | A |
| 39 | B | 99 | B | 159 | B |
| 40 | A | 100 | A | 160 | B |
| 41 | B | 101 | B | 161 | D |
| 42 | A | 102 | B | 162 | B |
| 43 | A | 103 | B | 163 | A |
| 44 | B | 104 | B | 164 | B |
| 45 | C | 105 | B | 165 | B |
| 46 | B | 106 | A | 166 | B |
| 47 | B | 107 | A | 167 | A |
| 48 | B | 108 | B | 168 | B |
| 49 | B | 109 | D | 169 | A |
| 50 | D | 110 | C | 170 | A |
| 51 | D | 111 | B | 171 | A |
| 52 | B | 112 | A | 172 | C |
| 53 | B | 113 | D | 173 | A |
| 54 | A | 114 | B | 174 | A |
| 55 | B | 115 | B | 175 | A |
| 56 | C | 116 | B | 176 | B |
| 57 | B | 117 | C | 177 | B |
| 58 | A | 118 | B | 178 | A |
| 59 | B | 119 | B | 179 | B |
| 60 | B | 120 | A | 180 | A |
NEET-Focused Electrochemistry MCQ Answer Key (20 Questions)
- B
- A
- B
- B
- A
- A
- A
- C
- A
- C
- B
- B
- C
- B
- B
- B
- B
- B
- A
- D
Disclaimer:
All MCQs are created for educational purposes. While designed to align with NCERT and NEET syllabus, students should consult textbooks and official exam materials for complete preparation.